Field of the Invention
The invention relates to a device for feeding printing forms to and changing them on a printing-form cylinder of a printing press, the printing-form cylinder being formed with a cylinder groove wherein a holding device associated with the start of printing is disposed, the holding device having an openable gripping zone formed as a gap extending over a format width of a respective printing form for receiving therein a leading edge of a printing form such as a printing plate.
The published European Patent Document EP 0 431 364 A2 describes a manipulation device for loading plate cylinders on rotary printing presses. A vertically displaceable and swivelably mounted robot arm, which is subdivided by at least one articulation into a plurality of parts, is provided on a guide and has an operating or manipulating head on a part thereof which is most distant from the guide. By means of this device, it is possible to remove printing plates located in elevated printing units of rotary printing presses of the turret or tower construction type.
The published German Patent Document EP 0 567 754 A1 discloses a device for feeding a printing plate onto a plate cylinder of a printing press. Included is an element for supporting and guiding a plate formed of at least one readily rotatable roller which, when in a plate changing position, has a side thereof which faces towards the printing unit disposed substantially on a straight line extending parallel to clamping surfaces of the device for taking up the leading edge of the plate which passes between the clamping surfaces and emerges inclined upwardly out of the printing unit. A suction cup may furthermore be arranged on this line as another element for holding and guiding the printing plate, a borehole via which the suction cup may be vented being provided in a rear region of this plate.
The published German Patent Document EP 0 570 702 A1 is concerned with a device for feeding printing plates onto a plate cylinder of printing presses, in particular, sheet-fed offset printing presses. On the plate cylinder which is movable into a given angular position, an insertion bar extending over the format width of the plate cylinder is adjustable at the outer peripheral surface of the plate cylinder in a print start region, so that the leading edge of the printing plate can be introduced by the insertion surface formed by this insertion bar directly into the gripping region of a print-start clamping bar. The outer peripheral surface of the plate cylinder thus forms with the insertion bar a funnel-shaped region for the leading edge of the printing plate. All the components respectively guiding and supporting the printing plate during the insertion thereof are arranged in front of the plate cylinder, which limits the accessibility thereof.